The present invention relates to a medical image radiography apparatus such as a circulatory system X-ray diagnostic apparatus and, more particularly, to an improvement in setting of a radiography position.
In angioplasty and the like, it is very important to provide a wide operation space for the operator and enable radiography of a blood vessel profile in an appropriate direction. For this purpose, in many circulatory system X-ray diagnostic apparatuses, a C-shaped arm for mounting a radiography system (an X-ray tube, an image intensifier, a TV camera, and the like) suspends from the ceiling. The C-shaped arm can perform many motions, i.e., vertical motion, main rotation motion, sliding rotation motion, and swing (isocentric rotation). The image intensifier (I. I.) can slide in the near/away direction. The bed top of a bed can move in the longitudinal and lateral directions.
Although these many movement elements provide a wide operation space for the operator and enable radiography of a blood vessel profile in an appropriate direction, they increase an operation load for the operator, and degrade the operability and reproducibility of the radiography position. The reproducibility of the radiography position is important when comparing a present radiography image with a past radiography image and subtracting a radiography image from a master image.
In order to reduce the operation load and improve the operability and the reproduciblity, a convenient function called automatic positioning is provided to most apparatuses. According to the automatic positioning function, the positions of the movement elements described above are preset as automatic positioning data to correspond to preset buttons. When a preset button corresponding to desired automatic positioning data is pressed, the positions of the movement elements are reproduced in accordance with the data.
Recently, as the radiography methods vary, the number of preset buttons tends to increase. Therefore, the correspondence between the automatic positioning data and the preset buttons becomes difficult to recognize. The operator must select a desired preset button from many buttons, leading to a cumbersome operation. This problem becomes more conspicuous particularly when radiography is repeated while successively changing the radiography position, as in an inspection for the circulatory system.
It is an object of the present invention to provide a medical image radiography apparatus in which the radiography position can be changed successively and easily.
In order to achieve the above object, according to the present invention, there is provided a medical image radiography apparatus comprising a radiography system for taking a medical image of a subject; a supporting mechanism for supporting the radiography system in various radiography positions; a memory unit for storing a plurality of radiography positions, together with an order relation thereof, as sequential automatic positioning data; and a controller for controlling the supporting mechanism on the basis of the sequential automatic positioning data in order to change a radiography position sequentially. In this manner, the plurality of radiography positions are stored, together with their order relation, as the sequential automatic positioning data. When taking a radiograph, the radiography position is sequentially changed in accordance with the sequential automatic positioning data. As a result, the operability concerning a change in the radiography position is improved more than in the conventional case wherein a preset button is repeatedly selected.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.